There are a number of commercial applications that utilize a controlled gas atmosphere enclosure. For example, in the semiconductor industry, gases are injected into an enclosed chamber, wherein one of the gases is plasmarized and strikes a target on a chamber lid causing the target's materials to deposit on a wafer. Other commercial applications include using controlled gases to cultivate biological cultures in an enclosed chamber, such as an incubator.
It is desirable to maintain optimal conditions inside the incubator in order to promote the desired growth of the cultures. In a conventional incubator, gassiest such as O2, N2, and CO2 are introduced from their respective tanks into the chamber depending on the growing conditions desired. Typically, the user sets the CO2 and O2 setpoints and appropriate gases are added.
Most biological incubators are either forced draft or water jacket. In the forced draft incubator, the inner space is lined with insulation instead of a water jacket. Heating of the chamber is provided by having a duct, a fan, and a heating element within the chamber. The air is typically circulated by the fan and heated by the heating element within the duct. The air is blown with more force than in the water jacket incubators in order to have more uniform circulation of the air and temperature in the chamber.
In the water jacket incubator, a water jacket surrounds the interior chamber of the incubator. FIG. 1 illustrates a conventional water jacketed incubator 100. The incubator 100 includes a cabinet 110, an interior chamber 120, a control system 160 and an outer door 150. The cabinet 110 has a set of leveling feet 145 to adjust the height or level of the incubator 100. The cabinet 110 contains a water jacket 125, (also shown in FIG. 3 at 380) which surrounds the interior chamber 120. The water jacket 125 is filled with water and is heated by a heater 155. The water in turn heats the air flow chamber (FIG. 3 at 395) where air can be circulated by air pump 175. Because water can be heated evenly, the water jacket 125 can evenly distribute the desired heat throughout the interior chamber 120. Such even heating is desired in order to provide a uniform temperature (for the biological cultures) throughout the chamber 120 and to prevent “cold spots,” which can cause condensation on the inner chamber walls.
The interior chamber 120 includes a humidity pan 135 that is filled with a liquid and provides moisture for the samples that are placed on a set of shelves 130. The shelves 130 are adjustable as wells as removable. A humidity sensor 180 is provided to monitor the amount of humidity in the chamber 120 so that adjustments can be made depending on the nature of the desired culture growth. A CO2 sensor 185 located in the interior chamber 120 can monitor the current CO2 levels so that CO2 can be replenished, as needed.
The control system 160 is provided on the cabinet 110 and includes an alarm system, a monitor system and a user interface. The outer door 150 and an inner glass door 140 provide access to the interior of the cabinet 110. The cabinet 110 has built-in sample port 175 and a front fill port 190. The front fill port 190 allows a user to fill the water jacket 125 with water or other liquids. The water can be drained at the lower portion of the cabinet 110 at a drain cap 195.
In order to drain properly, the drain cap 195 is at the lowest portion of the water jacket. If the water does not drain out from the water jacket, then mold, mildew or other growth can occur leading to contamination of the incubator 100. The operator has to bend down and manually turn the drain cap 195 in an awkward left-handed direction to remove the drain cap. Injuries can occur while opening the drain cap 195, such as back pains, should the operator not bend down properly, injuries to the hand and fingers should the drain cap 195 be stuck and difficult to rotate open. These injuries increase costs to the employers of the operator. Additionally, the operator (who can be a researcher) can require downtime to recover from the injuries and thus, important experiments may be delayed.
Therefore, there is a need for an apparatus and method to drain liquids from a water jacketed incubator that does not require the operator to bend down and perform an awkward maneuver. Additionally, there is a need for an incubator that can drain liquids from the water jacket without causing injuries to the operator.